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Post by jonathon haddock on Sept 8, 2004 14:07:35 GMT -4
I have a 81 camaro that I plan to try and get down the track this weekend. The problem that I am having is theie is a flat spot when I try and launch (approx 2000 rpm) off of the converter. It dosen't seem to be their when I tramp on it off idle. I have tried upgrading to a 50cc accelarator pump and increased the size of the "squirters" from size 25 to 37 it seemed to help some but the "bog" is still there. The motor is a 350 bored .030(flat tops), solid lift .494/494 230/230 duration cam. 1.5 roller rockers, performer intake and 1" spacer, 650 double pumper. The advance in the distributor is welded ahead<the flat spot was there previous to doing this> 17/8 headers<I had a set of 2"primary super comp headers on, until last week same no change> gear set is 4.56:1 with a 30 inch tall tire. the convertor is 3000 stall but I can't get that out of it. the car 60' at greenfield last year aroud 2.8/2.9 and one over 3.0 seconds and I know it has the potential of doing a hole lot better. when the car decided to go (bog included) it ran 13.4 @106. the car is gutted and weighs approximately 2900lbs. any help would be appreciated. thanks jonathon
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maritimedragracing
Junior Member
Associated Member
Racing under the Poverty Line
Posts: 42
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Post by maritimedragracing on Sept 9, 2004 16:50:22 GMT -4
Did you try changing the power valve? One minor backfire will wipe them out every time.
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Post by jonathon haddock on Sept 10, 2004 15:23:45 GMT -4
yes 2 or 3 times.
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Post by 88ss on Oct 20, 2004 15:59:05 GMT -4
Are your back barrels putting fuel in? Sounds like a timing problem - did you upgrade the system?? If not, try another ignition module and set the timing at around 35* total.
Is there any backfire associated with the bog? I assume you went through holley's troubleshooting pages online (www.holley.com). Your power valve might not be rated correctly for the engine's vacuum. Did you set up your idle with a vacuum gauge?
How do your spark plugs look? If their really sooty, your too rich, really white - lean..
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Post by Bad Influence on Oct 20, 2004 17:24:54 GMT -4
perhaps try checking the bowls and jets for dirt, another thing is perhaps the converter is not suited for the engine combination you have , perhaps try leaving at about 1500 rpm to see if it helps.
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Post by Road Rage Racing on Oct 20, 2004 17:56:03 GMT -4
You say your timing is locked? what is it set at?
Also when you changed power vavles, did you try
different sizes? or just put back what was in there
(6.5 probably)?
Oh and what's the rest of your fuel system like? stock pump? stock lines??
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Post by professor on Oct 22, 2004 7:56:07 GMT -4
Try adjusting the clearance between the pump operating lever
and the pump shaft, this should be about .010 ths. If it is to tight there is not enough pump travel and can cause a bog, set
clearance when idle speed is set on front barrals,or it will change when you set idle speed. Also on Holley carbs, the plastic cam that works the operating lever has a habit of wearing out and will not give enough travel to the pump, I have
seen this happen many times and most people never check for this problem because it is hard to see without looking for wear
signs, a worn out cam will not give the amount of fuel needed to run the engine from a dead stop. Professor
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